add bank readme

bank/README.md

@@ -0,0 +1,81 @@
+# Bank Module
+
+## Table of Contents
+
+* [Overview](#overview)
+* [How does it work](#how-does-it-work)
+* [How to send coins](#how-to-send-coins)
+* [Query commands](#query-commands)
+
+## Overview
+
+The bank module is responsible for handling multi-asset coin transfers between accounts. It exposes several interfaces with varying capabilities for secure interaction with other modules which must alter user balances.
+
+## How does it work
+
+```
+type MsgSend struct {
+	FromAddress types.HeimdallAddress `json:"from_address"`
+	ToAddress   types.HeimdallAddress `json:"to_address"`
+	Amount      sdk.Coins             `json:"amount"`
+}
+```
+
+[Handler](handler.go) for this transaction validates whether send is enabled or not
+
+Once the event is validated by the Handler, it will send a particular amount of coins to the sender
+
+## How to send coins
+
+One can run the following transactions commands from the bank module :
+
+* `send` - Send coin to an address.
+
+### CLI commands
+
+```
+heimdallcli tx bank send [TO_ADDRESS] [AMOUNT] --chain-id <CHAIN_ID>
+```
+
+### REST endpoints
+
+Rest endpoint creates a message which needs to be written to a file. Then the sender needs to sign and broadcast a transaction
+
+```
+curl -X POST http://localhost:1317/bank/accounts/<TO_ADDRESS>/transfers \
+  -H 'Content-Type: application/json' \
+  -d '{
+	"base_req": {
+		"chain_id": <CHAIN_ID>,
+		"from": <FROM_ADDRESS>
+	},
+	"amount": [
+		{
+			"denom": "matic",
+			"amount": <AMOUNT>
+		}
+	]
+}' > <FILE>.json
+
+heimdallcli tx sign <FILE>.json --chain-id <CHAIN_ID> > <FILE2>.json
+
+heimdallcli tx broadcast <FILE2>.json
+```
+
+## Query commands
+
+One can run the following query commands from the bank module :
+
+* `balance` - Query for bank balance of an address.
+
+### CLI commands
+
+```
+heimdallcli query bank balance [ADDRESS]
+```
+
+### REST endpoints
+
+```
+curl -X GET "localhost:1317/bank/balances/{ADDRESS}"
+```